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Continuous Dynamic Grid Adaptation for Regional Simulation in a Global Atmospheric Model. J. M. Prusa 1 and W. J. Gutowski 2 1 Teraflux Corp., Florida, USA 2 Iowa State Univ., Iowa, USA Acknowledgement: U.S. DOE Climate Change Prediction Program. Motivation figures.
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Continuous Dynamic Grid Adaptation for Regional Simulation in a Global Atmospheric Model J. M. Prusa1 and W. J. Gutowski2 1Teraflux Corp., Florida, USA 2 Iowa State Univ., Iowa, USA Acknowledgement: U.S. DOE Climate Change Prediction Program
Motivation figures Show Joe’s hurricane and globe slides
Key Procedure: Grid Transformation (vertical columns preserved)
Initial Development:Moisture (Tracer) Transport • Standard MM5 simulation • Drives off-line tracer transport using adaptive grid Iselin, J.P., 1999: Ph.D. Iselin, Prusa, Gutowski, 2002: Mon. Wea. Rev. Iselin, Gutowski, Prusa, 2002 (in prep.)
Using MPDATA advection • Pts(Leap-Frog) ~ 4 X Pts(Dynamic)
MM5 Leap-Frog (120 h; 52-km grid) MM5 Leap-Frog . [g/kg]
Dyn. Grid + MPDATA (120 h; 52-km grid) . [g/kg]
Current Development:Global ModelSmolarkiewicz et al, 2001: J. Atmos. Sci. • Anelastic, nonhydrostatic • Generalized coordinates • Non-oscillatory forward-in-time • MPDATA Eulerian advection
Current Development:Global ModelSmolarkiewicz et al, 2001: J. Atmos. Sci. Focus: Held-Suarez - #meridional cells (accuracy) vs. computational cost Qs: “Trf” vs. “Phy” on panel labels? If runs went 1080 days, why figs @ 200 d? gravity wave case?
Dynamic Grid StretchingConclusion & Directions • Markedly greater efficiency • Local constraints that ensure global conservation • Dynamic grid, include static focus region(s) • Geometric constraints (“flatness of space”) to reduce numerical noise